LTE (Long Term Evolution) is an evolution of 3GPP (The 3rd Generation Partnership Project) and a transition between the 3G (The 3rd Generation) technologies and the 4G (The 4th Generation) technologies. As a global standard for 3.9G (The 3.9 Generation), it further improves and strengthens air access technologies of the 3G. It adopts OFDM (Orthogonal Frequency Division Multiplexing) and MIMO (Multiple-Input Multiple-Output) as standards for evolution of its radio network. Currently, the LTE is gradually being considered as a mainstream technology for evolving to the 4G.
At present, in the field of mobile communication terminal products, a miniaturized LTE antenna design scheme that meets a lower frequency band, a higher bandwidth, and a higher performance is required to implement LTE technologies, particularly, in a frequency spectrum range of a low frequency band. In the conventional art, an LTE antenna design scheme may adopt, for example, a structure of an IFA (Inverted F Antenna). Multiple resonant branches of the IFA are printed on a PCB (Printed Circuit Board), and they and a longer ground cable that matches a low frequency band are connected in parallel to a feeding point. Although the ground cable can match the low frequency band, which increases a bandwidth of a low frequency band and improves efficiency of the low frequency band, this deteriorates a bandwidth and efficiency of a high frequency band. In the conventional art, a switch antenna also exists. Multiple different matching circuits are printed on the PCB, and each matching circuit matches a frequency band. The antenna is capable of operating in different frequency bands through a switch. However, the switch has an impedance effect and the introduction of the switch results in insertion loss. This affects the bandwidth and efficiency of the antenna when it operates in a low frequency band.